One type of standard fiber optic connector, which is commonly used in military applications, includes a cylindrical backshell and a strain relief mechanism formed by a pair of circular clamp elements lying at the rear ends of a pair of arms. When a circular fiber optic cable is used, the circular clamp elements are placed one above and the other below the circular cable and clamped to the cable.
Fiber optic flat ribbon cables have been found to provide many advantages over circular cables, as in providing easy splitting of the cable to route fibers in different directions. It would be desirable if an adaptor were available that could provide strain relief for fiber optic flat cables, using the existing backshell apparatus that was originally designed for clamping fiber optic circular cables. Such adaptor should retain all parts of the existing backshell apparatus.
In accordance with one embodiment of the present invention, a strain relief apparatus is provided, that furnishes strain relief for a flat optical cable, and especially when used with a standard fiber optic connector that has a cylindrical backshell and a pair of circular clamp elements for lying at the ends of arms to clamp to a circular fiber optic cable. The adaptor has a top face with a longitudinally-extending groove having front, rear, and middle portions. The flat cable is provided with a jacket that fits in the groove middle portion, the groove middle portion having a slightly greater width than the end portions to closely receive the jacket on the cable. The flat cable is clamped in place by forces applied downwardly against the jacket to clamp it against the bottom of the groove middle portion.
In one adaptor construction, the adaptor includes two identical adaptor elements that each forms a groove with middle and end portions. When the two adaptor elements are brought together, they clamp the jacketed cable portion between them. The two adaptor portions form a circular groove around themselves, which receives the circular clamp elements of the standard fiber optic connector.
Another adaptor includes a single adaptor element with a groove having front, rear, and middle groove portions that receive a cable with a jacket tightly wrapped around it. The jacketed cable portion is tightly pressed down by a wrap that extends around the rest of the adaptor, a shrink wrap sleeve being preferred. The single element adaptor has a front end with a pair of slots on either side that receive the arms of the standard connector. The circular clamp elements are held in place by placing one on top of the single adaptor element and the other on the bottom of the single adaptor element and holding them in place with screw fasteners.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.